Nanotechnology in Construction Engineering

Nanotechnology in engineering is for functional systems at the molecular scale. It is concerned with objects between 1 and 100nm in size (Nano meter). One Nanometer = 1 x 10-9m. The applications of nanotechnology in civil engineering are numerous. Let us look at some of the applications which are elaborated below.

Application in Concrete

As per the recent survey it is said that more of Nanoscale materials into cement can improve its performance; and the use of SiO2- nano could considerably increase the compressive for concrete, containing large volume of fly ash, at early age and improve pore size allocation by filling the pores between large fly ash and cement particles at nanoscale. The dispersal or slurry of amorphous nanosilica is used to improve separation resistance for self-compacting concrete. It has also been reported that by adding small amount of carbon nanotube (1%) by weight will increase both compressive and flexural strength.

The major concern of any civil construction today is cracking. The University of Illinois Urbana-Champaign is working on curing polymers that include a micro encapsulated healing agent and a catalytic chemical activate. When these microcapsules are broken by a crack, the healing agent will be released into that crack and contact with the catalyst. Polymerization is a bond with the crack faces. The self healing polymer could be particularly applicable to fix the micro-cracking in bridge piers and columns. But it requires costly epoxy injection.

Application in Steel

Steel is the major construction material; and its properties such as corrosion resistance, strength and weld ability are the essential for the design and construction. It is possible to develop new, low carbon and high performance steel (HPS). The new steel is developed with high-corrosion resistance and its welding ability by incorporating copper and nanoparticles from at the steel grain boundaries.

Coating

The coatings that incorporate Nanoparticles or Nano layers are developed for certain purposes in construction industry. It is one of the foremost applications of nanotechnology in civil engineering. For example, TiO2 is used to coat glazing because of its sterilizing and anti fouling properties. However, TiO2 will break down and crumble organic dirt through powerful catalytic reaction. Additionally, as it is hydrophilic, it allows the water to spread evenly over the surface and wash away dirt which is previously broken down. There are other special coatings that have been developed, such as anti-fraffiti, thermal control, antireflection and energy sawing coatings.

NanoSensors

These sensors are developed and used in construction industry to monitor or to control the environment condition and to check whether the materials in each structure are performing well. One of the advantages of these sensors is their dimensions (10 -9m to 10-5m). They can be easily embedded into the structures during the construction process. Smart collective and low cost piezoceramic-based multi-functional devices are applied to screen early age concrete properties such as temperature, relative humidity, moisture and early age strength development. These sensors can also be used to examine concrete corrosion, cracking and structure health monitoring. The Nanosensors are disclosed systems that can monitor internal stresses, cracks and other physical forces in the structures during the structures’ life; and are also capable of providing an early indication of the health of the structure before a failure of the structure can occur.